Evolution: earliest mammal ancestor found (Evolution)

by David Turell , Monday, August 01, 2022, 23:16 (634 days ago) @ David Turell

Appears to come from a lizard line forerunner:

https://www.livescience.com/mammal-ancestor-hippo-lifestyle?utm_campaign=368B3745-DDE0-...

"An animal that lived before the dinosaurs looked like a rotund lizard with a very small head and had a hippo-like semiaquatic lifestyle, according to fossils that were recently excavated in France.

"The amphibious animal, which represents a previously unknown genus and species of mammal ancestor, measured about 12 feet (4 meters) long, researchers reported in the October issue of the journal Palaeo Vertebrata, published online in July. They dubbed the new species Lalieudorhynchus gandi; it lived about 265 million years ago on the Pangaea supercontinent, just before the era of the dinosaurs.

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"From this partial but well-preserved skeleton, the paleontologists deduced that the primitive creature was a type of caseid — an extinct group of fossil reptiles that possessed mammalian traits and are thought to be mammal ancestors — in the genus Lalieudorhynchus. Described in the press release as a “chubby lizard” and as a 3.5-meter-long “pile of meat”, the creature lived during the Permian, a period that began about 299 million years ago and ended about 252 million years ago with the onset of the Triassic period (and the rise of the dinosaurs).

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"'The highly diverse group of mammal ancestors was the dominant group before the dinosaur ages," Frederik Spindler, co-author of the study and scientific director at the Dinosaur Museum Altmühltal in Denkendorf, Germany, told Live Science. When Spindler examined the newfound fossils, he concluded that they belonged to a new species. There have been fewer than 20 species of caseids identified in the fossil record to date; most came from the United States and Russia, but some have recently been found in southern Europe, Spindler said.

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"This newly identified creature is not a so-called missing link in any evolutionary lineage of the mammal family tree, but its status as one of the youngest caseids yet found may be significant for understanding mammalian evolution. "It increases the known diversity of large caseids, marking them as a very important herbivorous group," Spindler said. What's more, L. gandi could be the pinnacle of evolution for all caseids before they went extinct, meaning that the species had the most advanced features in the group, Spindler said." (my bold)

Comment: it is obvious mammals were fore deigned in the development of evolutionary stages. dhw will worry about the many branches that head into different directions. Not to worry, they al fit into ecosystems for a food supply for all, not just for humans.